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Review of the Central Pneumatics 21 Gallon, 120V 3HP Air Compressor
Harbor Freight recently had a sale on these (Harbor Freight Item # 94667),
and I was in need of a compressor with a decent reservoir. They list for $199 new, was on sale at $149.99, and
I also had a 15% off coupon, which brought this down to about $127.99 + tax. A GREAT deal for a
compressor with such a large tank if you ask me.
So, I bought it, and had no idea what to expect. I did not test it, or get to turn it on in the store
to see how loud it was, so, I was soon to find out. I will hopefully get in there soon with my laptop, and
see how many db's this is reading, as it is kind of loud, so I plan to keep it indoors and run the hose outside
for Halloween, by drilling a sealable hole in the side of the basement window to feed the hose through, this
may be a good idea anyhow, as it will keep the compressor out of the elements.
Specifications
| Working Air Pressure | 90 PSI |
| Maximum Air Pressure | 115 PSI with Auto Shut-Off |
| Air Tank Capacity | 21 Gallons |
| Air Flow Capacity | 7.0 SCFM @ 40 PSI
4.9 SCFM @ 90 PSI
4.3 SCFM @ 115 PSI |
| Motor | 3 HP Working / 5 HP Peak
120 Volt / 60 Hz / 14.3 A (load) / Single Phase |
| Required Circuit | Minimum 20 Amp (*Dedicated) |
| Pump Stage | Single |
| Air Outlet Size | 1/4” - 18 NPT |
| Accessories | Air Intake Filter
Air Hose Coupler |
| Shipping Weight | 152 Pounds |
| Power Cord | 12 gauge x 20’ |
| *A dedicated circuit is used only for a single load, for this compressor. Other loads on the circuit must be disconnected or turned off when the compressor is plugged in. |
Click this link for the User's Manual [pdf]
Hardware
It comes with no additional hardware (including oil), except for the built-in regulator, and a quick release. So, you
will want to grab a hose, some SAE 30 weight COMPRESSSOR OIL (not the crap for your car or the lawnmower), and whatever connections
and tools that you need.
Regulator, valve, and motor
Assembly
You will need an arc welder to assemble the two halves of the tank together.... just kidding. Assembly was easy. Just
unpack it from the box, and add the wheels to it, and you're good to go, AFTER you have added the oil. I am not kidding,
you will kill this instantly without oil. It requires 30 ounces of SAE 30 weight air compressor oil. Once you get near 30,
keep an eye on the level gauge on the front of the compressor. Once the oil level hits the red dot, stop.
ALWAYS CHECK YOUR OIL BEFORE USE! Too much or too little oil will cause you some problems. And will probably cost more
to fix than the compressor iteself.
The manual keeps chatting on about a dip stick, well, the manual must be outdated, as there is NONE. Just the oil level view window (shown in the photo below in the bottom right corner.)
Front of compressor, showing oil window
And that's it for now. Great compressor for the price. Waiting on some solenoids currently, so I can test out the life of a full tank
of air using a single pneumatic cylinder. I'll report back with more when I have it!

This page was last modified on: October 09, 2007 07:47:50 pm